A refillable container in the form of a refill cartridge for adhesive sticks is known from DE 41 16 581 A1. The reusable outer tube comprises a screwthreaded spindle which rotates on rotation of a knurled nut arranged at the closed end of the container. The replaceable part, i.e. the inner tube, comprises the plunger with the internal screwthread in which the screwthreaded spindle engages to displace the plunger towards the open end of the tubular container opposite the knurled nut and hence to push out the adhesive from the open end.
The known container is in the form of a refill container for an adhesive stick intended for use on paper. The following procedure is adopted to refill the container. The knurled nut is rotated until it no longer engages in the internal screwthread of the plunger. The empty inner tube is then withdrawn from the outer tube together with the plunger. A new inner tube filled with the adhesive and comprising a plunger with a central screwthreaded bore is then introduced into the open end of the outer tube until the upper end of the screwthreaded spindle fixedly connected to the outer tube comes into contact with the internal screwthread of the plunger. By turning the knurled nut, the screwthreaded spindle is screwed into the internal screwthread of the plunger and into the adhesive. At the same time, the inner tube continues moving into the outer tube until it reaches its final position in which nipples arranged on the inner wall of the outer tube snap into correspondingly shaped depressions in the outer wall of the inner tube. The inner tube is thus fixed inside the outer tube so that the inner tube cannot be longitudinally displaced or rotated relative to the outer tube. To remove the adhesive, the knurled nut is then rotated in the opposite direction so that the plunger moves towards the open end of the inner tube and pushes out the adhesive.
The disadvantage of the known container lies in the time-consuming screwing movement involved in the fitting of a new refill cartridge. Accordingly, the user is often not prepared to fit a new refill cartridge to the empty container, instead the container as a whole is discarded and a new complete container is used instead. This means that the purpose of the known container, namely to reduce waste, is often not fulfilled.
Accordingly, the problem addressed by the present invention was considerably to simplify replacement of the inner tube in a container of the type mentioned at the beginning.